AW: [Retros] An error in a famous problem

[Gerd Wilts]

Hello,

in order to open the retro cage the move Nb3-a1 must be retracted. Can you please give
the retro play until that move? It is difficult to check, but it seems that at least in
some of your cooks the move Nb3-a1 may not be retracted anymore.

Best,

Gerd Wilts
 

> I found an error in Gyula Breyer's famous retrograde problem (see

> http://www.mathpuzzle.com/retrograde.html).

> In the original problem, only the last 44 moves (not 50) are 

> without pawn move

> or capture:

>